A Colombo crime family associate who celebrated his stunning acquittal on double federal murder raps last year was singing a different tune Monday after a seething judge nailed him with a 14-year sentence for drug peddling.

Francis B.F. Guerra and his family members had reveled in his remarkable acquittal last year and had expected a relatively light sentence for the lesser narcotics charges he was eventually convicted of at the same trial.

But despite the jury’s verdict, Judge Sandra Townes told Guerra yesterday that she was absolutely convinced he took part in the gangland killings of a former Colombo underboss and a Staten Island nightclub honcho.

“It was proven at trial in my mind that you were involved in these murders,” Townes told the incredulous goon before laying down her sentence.

The jurist said that she broached the slayings because they figured into her assessment of Guerra’s future risk to society.

“He does the bidding of the Colombo crime family,” Townes said of the dazed defendant. “My belief is that when he is released he will go back.”

Guerra — who was convicted of selling Oxycodone pills — looked floored after Townes walloped him with the long prison stretch. He had faced from a minimum of time served up to 20 years.

Defense attorney Gerald McMahon slammed Townes and the sentence.

“This is an atrocity,” he seethed, “It’s a disgrace for her to tell the jury that said he’s not guilty that he’s guilty,” he said of her references to the killings.